Current-modifier.



OLM. LEIGH. CURRENT MODIFIEB. APPLICATION man um. ms.

1,271,732. Patented July 9, 1918.

2. 2 SHEETS-SHEET I.

I Qrpar/YZee/Lch 0. M. LEICH. CURRENT MODIFIER. APPLICATION FILED 0.24. 1915.

Patented J 1115' 9, 1918.

2 sums-shin 2.

UNITED STATES PATENT OFFICE.

OSCAR M. LEIGH, 0F GENOA, ILLINOIS, ASSIGNOR T0 LEIGH ELECTRIC COMPANY, OF

. GENOA, ILLINOIS.

CURRENT-MODIFIER.

Specification of Letters Patent.

Patented July 9, 1918.

To all whom it may concern:

of Illinois, have invented a certain new and useful Improvement in Current-Modifiers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, formlng a part of this specification.

My invention relates to current modifiers, and-in one form of its application is of particular use in providing a vibrator for instance which can be operated directly from an alternating current circuit and provide intermittent or pulsatory current of a frequency other than that of the source. Even more specifically, my invention finds great application in connection with vibrators used for signaling purposes in telephone exchanges or similar places, and my invention will be readily understood if in the description which I will now give I will explain it more particularly as applied to such a telephone vibrator.

When my invention is thus applied, I may say that in one specific case I operate the device from a sixty cycle alternating current which operates. a vibrating element. Current from the source may then be led through a suitable rectifier if it is desired to rectify the current, and this rectified current will be then be reimpressed on the ringing circuit through the interposition of switching or similar elements controlledby the vibrating element aforesaid.

In a divisional application hereof Serial No. 98,266, filed May '18,- 1916, I..,s l row.a structure similar to that disclosed herein, in which the claims however are based more particularly on the feature of having the rectifier controlled by vibratory means as shown in Fig. 2 of the drawings herein.

I will explain my invention more in detail as applied to two specific styles of rectifiers by referring to the accompanying drawings, in which- Figure 1 diagrammatically sets forth my invention in connection with an electrolytic rectifier, and

Fig. 2 is a similar view with an electromagnetic rectifier.

Referring to Fig. 1, I have a source of a alternating current which preferably is of the sixty cycle, one hundred and ten volt type as supplying current to the conductors 2 and 3. I show a ringing circuit having the conductors 4: and 5 which when my invention is used for telephone purposes lead directly to the switch board, where through the interposition of ringing keys these conductors 4 and 5 are connected with the telephone line to call the substation signal as is customary. I might say here that my improved device can supply the current at any desired frequency so that it may not only be used for operating the ordinary polarized bells of telephone receivers, but may also operate harmonic ringers or similar devices as may be required.

One great advantage in the use of my vibrator as will appear presently resides in the fact that the vibrator requires a practically negligible no-load current so that the expense of operation is reduced to a minimum. I show a rectifier 6 which may be. of any desired type of rectifier, but which herein is of the electrolytic type having the jar 7, the lead electrode 8 and the two platinum electrodes 9 and 10. It is well known of course that with the platinum electrode in the electrolytic cell current of one direction only passes therethroughf The rectifier is used in connection with two impedance coils 11 and 12 which'are directly or inductively connected across the conductors 2 and 3, thecircuit being traceable from the conductor 2 by way of the conductor 13, impedance coil 11, impedance coil 12, conductor 14, to the line conductor 3.

I have provided a vibrating element 15 consisting of a spring which may be tuned to-a certain frequency if desired so that if actuated electro-magnetically it will vibrate with said frequency. A permanent mounting 16 is provided for this sprin This spring carries a contact element 1? which in conjunction with the stationary back contact 18 controls the circuit through coils 19 and 20 forming the energizing coils of an electromagnet 21. The circuit through the coils 19 and 20 may then be traced from the line conductor 3 by way of conductor 22, coils 19 and 20 in parallel, by way"of conductor 23 to the spring 15, the spring contact 17, the back cont-act 18, and by way of conductors 24 and 13 to the line conductor 2. It will thus be seen that the current from the source is used directly to actuate the vibrating element 15. This vibrating element 15 'l9 and 20 are each preferably of high resistance, for instance one thousand ohms each so that vvery little no-load current is required to actuate the. spring 15. The spring 15 carries an iron armatur 26 which coiiperates with the cores of the coils 19 and 20? The electro-magnet 21 in addition to the keeper 27 is provided with a third leg 28 so that the armature 26 is more or less uninfluenced by the alternations of the current from the alternating current source, the rate of vibration depending upon the spring 15 and the energization of the coils 19 and 20 being controlled by the cooperation between the elements 17 and 18 as in the ordinary vibrating bell. One of the coils, the coil 19 for instance, has a condenser 29 included serially therewith so as to throw the currents in the coils 19 and 20 out of phase so that there is never a dead point in the energization, and the third leg 28 assists further in cooperating toward this end. The armature 26 thus is actuated by the coils 19 and 20 as the circuit through said coils is controlled by the elements 17and 18 irrespective of the alternating character of the current threading said LCOllS. The vibrator 15 carries circuit controlling springs 30 and 31 which cotiperate with back contactsv 32 and 33. The springs 30 and 31 are insulated from the vibrator 15, are electrically connected together however, and connected by means of the conductor 34 with the intermediate junction point 35 of the impedance coils 11 and 12. The impedance coils 11 and.

12 of course are of sufiicient impedance that their no-load requirements are very small. The aluminum electrode 10 is directly con-v nected by means of the conductor 35 with the conductor 14 leading to the line conductor 3. The aluminum electrode 9 is. intermittently connected with the other line-conductor 2 in accordance with the operations of'a relay 36, this circuit being traceable from said electrode 9 by way of conductor 37, contact spring 38, front contact 39, conductor 40, to the conductor 13 which leads directly to the line conductor 2.

- Thus wheneverthe'relay 36 is energized the electrolytic cell is directly in bridge of the mains 2 and 3. I provide a transformer windings 42 and 43 and the secondary winding 44. The coils 42 and 43 are connected in parallel except that they are differentially connected as shown with a free terminal of each leading respectively to the front contacts 32 and 33. The remaining terminals of these primary coils 42 and 43 are connected together and then connected by means of the conductor 45 to the lead electrode 8. The secondary Winding 44 has one terminal'dii ectly connected to the ringing lead 5"=and'-'its other terminal is connected to thearmature 46 of the relay 3 6. The. armature 46 co? operates with a front contact 47 This relay 36 has two coils respectively 48 and 49,

the coil 48 being low wound, say fifty ohms, and the coil 49 being high wound, say one thousand ohms.

Nowit will thus be seen that initially the circuit through the secondary winding 44 can be traced from the ringing lead 4 through the coil 48, the coil 49, secondary 44, tothe conductor 5. If a ringing circuit is established across the leads 4 and 5, then the relay 36 attracts its armature 46, thereby short circuiting the coil 49 so that the secondary winding 44 furnishes its current directly to the leads 4 and 5 through the interposition merely of the fifty ohmcoil 48 whose magnetism however is sufiicient to hold the armature 46 so long as the circuitacross the leads '4- and 5 remains closed. I may say that the transformer 41 serves to change the voltage as may be required and I find in one form of the device that I have satisfactory service if the coils 42- and 43 each have eight hundred turns, whereas the winding 44 has twelve hundred turns.

1 may say also that the solution which I use in the electrolytic cell may preferably be ammonium phosphate. 1 may say also that in the continuous operation of the electrolytic cell 6 sediment forms which collects at the bottom and which must be periodically removed. amount of sediment thus thrown down, the primary circuit through the electrolytic cell is normally maintained open by the elements 38 and 39 of the relay 6. The no-load current to operate this device would he that consumed by the electromagnet 21 and that flowing through the coils 11 and 12. There is also a slight no-load current through the circuit including the elements 8, 10, 42, 32

In order to reduce the' and the coil 11. This no-load current isless explained. It is to be remembered that the coils 42 and 43 are connected to the lead electrode 8 and respectively to the contacts 32 and 33. Thus as the vibrator moves to and fro one coil 42 and then the other coil 43 is connected between the lead electrode 8 and the junction point 35 between the impedances 11 and 12. There is thus a pulsatory rectified current passing through the coils 42 and 4 3. The coils 42 and 43 however are differently wound and thus their effects are of opposite sign on the winding 44 even though these coils receive their current at times from the platinum electrode 9 and at 'other times from the platinum electrode 10.

It must be remembered of course that the vibrator vibrates 1n accordance with its predetermined frequency .or rate of vibration entirely unaffected as to whether the break at theelements17 and 18 occurs at the peak of the wave or at any other time, this vibrator not necessarily operating in synchronism with the cycles of current fur-. nished by the source 1. p

' Assume however that the elements 31 and 33 are infcontact throughout the course of two or three cycles of alternating current, at that time the coil 43 is in circuit and receives several impulses all in the same direction however, alternately from the platinumelectrode 9 and-the platinum electrode 10. There is thus a uni-directional pulsating current traversing the coil 43 of a given sign. The next instant when the elements and 3.2 are in contact there is a similar,"

uni-directional pulsating current in the coil 42, but on account of its reverse connection the magnetic effect is opposite to that of the coil 43 so thata current of opposite sign follows through the winding 44. Thus for instanceif it were desired to transform the sixty cycle current of the source into a l twenty cycle rin ing current, then the vibrator 15 would" etunedgto cause a transferenc of current iromone coil 42 to the other coil 43 and vice versa, once during each three cycles so that coil 42 for instance would receive three ,pu'lsations of similar sign, and then coil 43would receive three pulsations of a similar sign whose magnetic efl'ects however would be of opposite sign.

Referring now ;to Fig. 2, I have shown my invention as used in connection with an electro magnetic rectifier 50 having the operating coils; 5'1 and 52 vwhich control a polarized armature 53.' The. armature 53 cooperates with contact elements 54 and 55 to send a rectified current byway of the conductor 45 through the primary coils 42 and 43 respectively. A polarized magnet 56 is indicated. Similarly to the arrangement of Fig. 1 the rectified .;current in the winding 42 produces the oppositekind of a field to that produced in the coil 43 by reasonof the reverse connection of,these two coils as is The armature 53 of course vibrates clear.

, with the ,frequency'of the alternating cur- J-Irentand-thus the impulses of alternating tified currentxby way of the conductor 45.

current are rectified so as to establish a recrom what has been described it is thought the nature of my invention will be readily clear to those .skilled in the art and it will also be clear that many modifications may be made within the scope of the appended claims without departing from the spirit of my invention. Having however thus described one form which my invention may take, what I claim as new and desir'e to secure by Letters Patent is: 1. In a frequency changer the combination with a source of alternating current, a rectifier to rectify current from said source, a consumption circuit, means to change said rectified current into analter nating current for said consumption circuit,

and means controlled by the current in said consumption circuit to control said rectifier.

.2. In a frequency changer the combination with a source of alternating current, a

rectifier to rectify current from said source,

tion with a source of alternating current, a

rectifier to rectify current from said source a consumption circuit, means to change said rectified current into an alternatin current for said consumption circuit, an means controlled by the current in said consumption circuit to control said rectifier, said meansincluding a relay having a high resistance and a low resistance windin and means for short circuiting said hig sistance winding. L p

4. In a frequency changerthe combination witlf a source of alternatin current, a rectifier to rectify current rom said source, a consumption circuit, means operated from said source to change said rectified current into an alternating current for said consumption circuit, and means controlled by the current in said consumption circuit to control said rectifier, said means including a relay having a high resistance and a low resistance winding.

In witness whereof, I hereunto subscribe my name this 12th day of February, A. D. 1915. i

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